Tropical lightning storms sweep the south amid weather warning ahead of 26C African plume

TROPICAL lightning storms lit up skies across the south overnight into Monday as forecasters issued a weather warning ahead of 26C sunshine later this week.

Heavy rain is sweeping across parts of the country, with warnings of flash floods - days before a scorching plume of heat from Africa arrives.

A yellow alert, which covers the area between London, Oxford, Cardiff and Plymouth, was in force until 5am.

The Met Office says there could be "sudden flooding" after weeks without significant rain.

Some areas may also see bizarrely unseasonal May hailstorms - while one lucky weather-watcher spotted an ultra-rare "moonbow" in Alston, Cumbria.

The phenomenon is caused by Sunday night's Blood Moon illuminating droplets of water before its eclipse in the early hours of this morning.

Kelly Shaw sent the image to the Met Office. Meteorologists replied: "They're a rarer occurrence than the standard rainbow due to the conditions required for them to form.

"The amount of light available even from the brightest full moon is far less than that produced by the sun so moonbows are incredibly faint and very rarely seen."

Stunning photographs of the tempest have also been shared on social media.

One Twitter user posted footage of the storm crackling through the sky above the coastline in Southbourne, Dorset.

In nearby Weymouth, a flash momentarily made the pitch-black night appear as if it was daytime.

Emma Prowse captured a fork of lightning about Fareham in Hampshire. She wrote: "Some pretty solid storm action."

The Isle of Wight has been illuminated by purple flashes, while a social media user in the West Country likened the storm to a scene from science fiction.

"There's some War of the Worlds stuff going on in Somerset," she said.

"Eerie silent lightning."

Forecasters said on Sunday: "Although the locations affected by thunderstorms remains uncertain, a few places may experience a combination of heavy rain, frequent lightning and hail during Sunday night.

ULTRA-RARE 'MOONBOW'

"Should thunderstorms develop, they are likely to move north from the south coast during Sunday evening into parts of south Wales, southern England and East Anglia overnight before gradually weakening during Monday morning.

"Whilst some places will remain dry, a few places may see 20 to 30mm of rainfall in less than an hour, with frequent lightning and hail additional hazards."

The grim weather could cause damage to buildings from lightning strikes.

And the Met Office has urged those travelling to take extra care overnight and early on Monday.

Some roads may be forced to close and driving conditions could be challenging. Train and bus services may face delays and cancellations.

'EERIE SILENT LIGHTNING'

The squall will be a shock to the system for most Brits after balmy sunshine on Saturday.

Temperatures hit a summery 23.5C in Northolt, West London.

That's just shy of the 23.6C recorded on May 6 in Faversham, Kent, the hottest day of the year so far.

Met Office meteorologist Simon Partridge said the abrupt change in weather comes courtesy of "a plume of warm and humid air coming off the continent".

"That's going to allow some heavy showers to develop and the odd rumbling of thunder as well," he said.

STUNNING SHOTS

This week, temperatures are set to soar once again amid a steamy heatwave.

The warmest day of the year so far is expected on Tuesday, when highs of 27C are predicted.

It will make Blighty hotter than holiday hotspots Barcelona and Lisbon, where temperatures will struggle to surpass 23C.

Met Office meteorologist Aidan McGivern said: "During the early part of the week it’s possible to see low to mid 20s fairly widely, and high 20s around the South East if we get sunshine associated with this plume.

"However, as I mentioned, it does bring the threat of thundery outbreaks at the same time."

His colleague Alex Deakin said "warm and humid air" will likely "spark some heavy, thundery showers".

The Met's long-range forecast has predicted warm temperatures to last until May 23.

But the hot sun will also be accompanied by a "pollen bomb" which will cause misery for hayfever sufferers, experts predict.